The present invention relates to an axial sealing arrangement for a rotary-piston engine. A sealing member is movably disposed in a groove provided in one of two components that have opposing parallel surfaces which move relative to one another. The sealing member, in cooperation with sealing bolts disposed at its ends and at bends of the seal boundary formed by the sealing member, seals the associated chamber from the clearance between the parallel surfaces of the components, and thus from the other chambers of the engine.
In internally sealed engines, these grooves extend along the side walls of the rotors or pistons substantially parallel with and close to the edges of the piston flanks. Springs are provided at the bases of these grooves to press the sealing members in such a way that their contact surface will bear against the side walls. At the operating pressure in the associated chamber, the pressurized working medium which enters the groove presses the sealing members againt the radially inner groove wall that is remote from the working chamber, while the contact surface of the sealing members bears against the side wall along which they slide. This seal thus always closes in the manner of a valve when the chamber associated therewith is in the pressurized operating condition.
This condition, however, creates the following problem: between the groove wall and the sealing member there is an oil film which the pressure in the chamber acts upon from the base of the groove, so that a counter-pressure opposing the bearing pressure on the sealing member, and thus a pitching or tilting momentum, will be created on that side of the sealing member which faces the base of the groove. This momentum urges that side of the sealing member which bears against the contact surface away from the chamber and subjects it to torsional stress inside the groove, possibly accompanied by frictional forces. The sealing members are therefore lifted, from the base of the groove, off the groove wall which they are expected to bear against, under the effect of the oil film, which dams up in a wedge-shaped manner. This results in considerable leakage loss of pressurized gas, and in a corresponding charging loss in chambers operating in the intake mode.
Proposals to eliminate these problems have not become known.
It is therefore an object of the present invention to prevent the establishment of a leakage path via the base of the groove of the sealing members as well as between their contact surfaces and the low-pressure groove side.